Burglar-alarm.



PATENTBD NOV. 8, 1904.

T. JOHNSON.

BURGLAR ALARM.

Arl monlpu FILED APR. 2, 1904.

R0 MODEL.

WlTNESSES:

ATTORNEY UNITED STATES Patented November 8, 1904.

PATENT OFFICE.

BURGLAR-ALARM.

SPECIFICATION forming part of Letters Patent No. 774,668, dated November8 1904.

Application filed April 2,1904- Serial No. 201,301. (No model.)

To all whom it may concern:

Be it known that I, HARRY T. J OHNSON, a citizen of the United States,and a resident of Jersey City, Hudson county, New Jersey, have inventedcertain new and useful Improvements in Burglar-Alarms, of which thefollowingis a full, clear, and exact description, reference being had tothe accompanying drawings, forming a part of this specification.

My invention relates to that class of devices which are employed toclose the circuit in electric-burglar-alarm systems and give an alarmwhen some movable object, such as a window, is moved to obtain access toa room or building. It has been especially designed and is peculiarlyadapted for use with a'window-spring, and it may be employed with thewell-known types of such springs as well as with the particular form ofspring herein illustrated.

The invention as herein illustrated forms a component part of awindow-spring; and the object thereof is to provide for such acircuitclosing device as I have referred to an auxiliary switch orcut-out by means of which the circuit-closing device may be thrown outof circuit Without removing the window-sash or the spring, thus enablingany short circuit or improper contact to be readily located.

A further object thereof is the provision of means by which the circuitmust be reestablished before the sash can be returned to its normalposition.

1n the drawings, Figurel is a sectional elevation of a window-springembodying my invention with the parts in the position they assume whenthe sash is in its normal or closed position, the contacts being open,but connected with the circuit. Fig. 2 .is a similar view in elevationwith the partsin the position they assume with the sash opened, thecontacts being closed, but disconnected from the circuit; and Fig. 3 isan elevationshowing both the upper and lower sashes in section and opento their full extent.

Similar reference characters are employed to designate correspondingparts in all the views.

The particular form of device which I have selected for purposes ofillustration and description is a window-spring adapted to be secured ina suitable recess in the window-frame and comprises a plate 1, providedwith a slot 2, in which is pivoted a contact-lever 3. Aninsulating-bearing 4, consisting of a revolu ble disk of fiber or othersuitable material, is mounted in a slot 5 in the lever 3.

A spring 7 and aspring contact-arm 8 are secured to the plate 1 by theeyelet 9, conducting-washer 10, insulating-bushing 11, andinsulating-washer 12. One of the line-wires, 14, connectswith theconducting-washer 10. The other line-wire, 15, connects with thespringtongue 16, which is secured to the opposite end of the plate 1 bythe eyelet 17, bushing 18, and insulating-washer 19. Amovable contactmember 22 is carried by the plate 1, and

nection with the line-wire 15 through the tongue 16, contact 22, andplate 1. The movable contact 22 in the form herein illustrated consistsof a screw threaded stud passing through the plate 1 and provided at itsouter.

end with a slotted head, which furnishes a means by which the stud maybe screwed in and out to make the contact, as shown in Fig. 1, or tobreak it, as shown in Fig. 2. The inner end' of the stud is enlarged orsuitably upset to prevent the stud from being screwed out of the plate.The spring is secured in place by screws which pass through the eyelets9 and 17.

Each window-sash is provided with a recess which is so located that whenthe sash is closed the recess will be opposite the lever 3, whichwill-be held so as to project therein by the pressure of the spring 7 onthe insulated bearing 4:. In this position the circuit is open. When thesash is raised, the side ofthe sash will bear against. the lever $.andforce it into contact with the arm 8, asshown in Fig. 2, thus closingthe circuit, the lever 3 and the arm 8 forming the main orsash-controlled contactsof the window-spring.

In Figs. 1 and 2 the window spring is shown in the position it occupieswhen applied to the lower sash 28.

the upper sash the position of the spring 1s j reversed, as shown inFig. 3, 1n whlch the 1 In applying it to i.

Heretofore in case of derangement of one 1 or more of the springs, sothat the circuit is lmproperly closed or improperly held closed, it hasbeen necessary in locating the defective or inoperative spring to removeeach windowsash, including the mrting-strips, and sometimes each spring,one after the other until the discovery of the defective spring. As alarge number of springs are usually employed on the same system, thelocation of a defective spring has been diflicult and expensive, owingto the time consumed. My invention enables such a defective orinoperative spring to be located accurately and quickly. By opening oneof the window-sashes, so as to expose the end of the auxiliary contactmember 22, and turning the contact 22 so as to carry it out ofengagement with the tongue 16, Fig. 2, the circuit will be broken atthat point. If the line be then tested in the usual manner by closingthe testing-switch and it with all the other sashes closed the alarm Yfails to operate, it will be apparent that the other springs are in goodorder and that the trouble must be 1n the spring being tested. If,however, the alarm sounds, then it is ap parent that the circuit isclosed at some,

other spring, and the springs are tested in a similar manner one afterthe other until the trouble is located, when, if necessary, the springis removed in the usual way and put in order.

By arranging the movable contact 22 so that when the circuit through thespring is broken the contact will project into the path of thewindow-sash it becomes impossible to close the window until the contact22 shall have been restored to its normal position. If, therefore,through carelessness the spring should not be reconnected with thecircuit, its condition would be discovered when attempting to close thewindow.

Having thus shown and described my invention, what I claim as new, anddesire to secure by Letters Patent, is

1. A window-spring provided with sashcontrolled contacts, and auxiliarycontacts free from the control of the sash and comprising a membermovable into the path of the sash when the circuit is broken.

2. In a window-spring, the combination of a plate, a sash-controlledcontact carried thereby and an auxiliary movable contact accessible fromthe front of the plate for controlling the circuit through thesash-controlled contact.

3. In a window-spring, the combination of a plate, a sash-controlledcontact carried thereby, and an auxiliary contact movable through theplate into the path of the sash.

4. In a window-spring, the combination of a plate, asash-controllei'lcontact carried thereby, an auxiliary contact and means for moving theauxiliary contact to break the circuit to the main contacts and to forma stop to prevent the closing of the sash until the circuit is closed.

5. In a window-spring, the combination of a plate, a sash-controlledcontact carried thereby, a screw-stud carried by the plate and movableinto and out of the path of the sash to break and make the circuitthrough the spring.

6. In a window-spring, the combination with the plate and thesash-controlled contact carried thereby, of a contact insulated from theplate and a contact carried by the plate and in contact therewith,movable into and out of engagement with the insulated contact to makeand break the circuit independently of the sash-controlled contacts.

HARRY T JOHNSON.

\Vitnesses:

G. REINHARDT, O. H. Horwoon.

